hahaha the article is in Novembers Scientific American its pretty good article. Covers alot of info on worldwide capabilities. Its really just a head with different materials and different primary chemicles. Basically they are saying they are unsure of the shelf life of the older warheads so they want to replace them with ones they dont feel they would be unsure about. Mostly since you can no longer test them. I get frustrated when a magazine or news channel trys to force their opinion down your throat during news of any type. The article starts out with “the us needs a new defense strategy, not new nuclear warheads.” maybe maybe not i dont care i want to read the article and make my own opinions. Not be forcefully subjected to others. Oh well